For whom may be interested in this topic, I did buy a Magewell card. It worked. I captured from my video camera. The price I got is lower than Blackmagic.
Recently, I am going to purchase a 4k HDMI video capture card for private use. I was advised to choose the 4K video capture card from Magewell. I need the capturing no choppy and no lag. Does this card can fit my request and any other suggestions are welcomed. Thx.